1. Field of the Invention
The present invention relates to a sputtering film forming method for forming a thin film, an electronic device manufacturing method, and a sputtering system, with regard to such as a semiconductor device manufacturing process.
2. Description of the Related Art
A development of a technology for microminiaturization of a semiconductor is being carried out at present at a furious pace, in order to achieve ever-greater speed and ever lower power consumption with LSIs. With regard to a conventional transistor, a silicon nitride film is employed as a gate insulator film thereof, and a polycrystalline silicon film is employed as an electrode thereof. A silicide, which is chemical compound generated by silicon and a metal, is employed for reducing a resistance of a diffused layer and reducing a contact resistance.
In recent times, however, a development is being carried out on a transistor technology that combines a metal gate electrode and a high-k gate dielectric films, in order to keep control of an increase in an electric current leakage, owing to an increasing thinness in the gate dielectric layer, and a decline in an electric current driving force, which is caused by a slight surface depletion of the polycrystalline silicon. Moreover, a search of a new silicide material is being carried out in accordance with a miniaturization of a semiconductor device.
Given such a circumstance, an establishment of a metal/high-k gate stacks manufacturing technology and the silicide manufacturing technology has been desired, one that is primarily capable of a design and a control with a high precision that is required in the development of the preceding transistor technology.
A sputtering system may be cited as an instance of a thin film forming method with regard to such as a semiconductor apparatus. Refer to Japanese Patent Laid Open No. 2005-8943. An instance of a conventional multi-cathode type sputtering system is depicted in FIG. 1.
When using such a system to perform a film thickness design with such as a semiconductor, it is necessary to form an inclining film thickness. In order to perform a film forming that incorporates the inclining film thickness, the conventional apparatus that is depicted in FIG. 1 is employed, and the inclining film thickness is achieved by performing an inclining sputter, wherein a target is put out of parallel to a substrate, and the substrate is anchored in place. A film thickness distribution of a hafnium stack that is obtained in such a manner is depicted in FIG. 2. Furthermore, a technique has been sought such that, in an instance where stack films are formed from two different types of material, a determination is made of a characteristic point so as to form the second layer on the first layer, which is depicted in FIG. 2, in such a manner that the thick of a location of the first layer will correspond to a thinnest location of the second layer. A film thickness distribution of a stack of a hafnium film and a tantalum film that is obtained in such a manner is depicted in FIG. 3.
When performing such a film forming method, however, with respect to the film thickness distribution of each respective monolayer, a contour line that joins a location with an equivalent film thickness ends up forming an arc shape, such as is depicted in FIG. 2, and it has been difficult to obtain a film that comprises a given film thickness incline in only a single direction. Accordingly, when depositing a film that includes an incline of a film thickness in two directions in a plane of the substrate, it has of necessity not been possible to obtain a satisfying film thickness distribution.
Hence, given that the thickness control of the stacked film is insufficient in a circumstance of, for instance, a thin film manufacturing technology of the stack films on an order a plurality of nm, such as the metal/high-k gate stacks, an imprecision arises in the plurality of stacked film thickness. As a result, an impediment arises to an operation that determines a stack construction, which is required for high precision design and control.